Fracture characteristics and fracture interface buckling mechanism of cantilever rock mass under non-uniformly distributed load

This study examined non-uniform loading in goaf cantilever rock masses via testing, modeling, and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure. The study investigates the non-uniform load gradient effect on fracture characteristics, including load characteristics, fracture location, fracture distribution, and section roughness. A digital model for fracture interface buckling analysis was developed, elucidating the influence of non-uniform load gradients on Fracture Interface Curvature (FIC), Buckling Rate of Change (BRC), and Buckling Domain Field (BDF). The findings reveal that nonlinear tensile stress concentration and abrupt tensile-compressive-shear strain mutations under non-uniform loading are fundamental mechanisms driving fracture path buckling in cantilever rock mass structures. The buckling process of rock mass under non-uniform load can be divided into two stages: low load gradient and high gradient load. In the stage of low gradient load, the buckling behavior is mainly reflected in the compression-shear fracture of the edge. In the stage of high gradient load, a buckling band along the loading direction is gradually formed in the rock mass. These buckling principles establish a theoretical basis for accurately characterizing bearing fractures, fracture interface instability, and vibration sources within overlying cantilever rock masses in goaf.